I will guess 400 mm, 1.7X converter, with 1.5X DX crop factor ... But like others would be interested to know which lens, whether hand-held or tripod-mounted, etc. I occasionally photograph a flock of herons who live nearby, but lately have noticed that I've been coming home with more and more photos of the gulls that fish, scavenge, and perch in the same area. They're graceful in flight, and often quite expressive just standing around. These are great photos!

Thank you. I had 300/2.8VR + TC-20E III + TC-17E II stacked. If we take the crop factor into account the effective focal length would be 1530 mm. The TC-17E II has required Dremeling one tab off the mount.

I will guess 400 mm, 1.7X converter, with 1.5X DX crop factor ... But like others would be interested to know which lens, whether hand-held or tripod-mounted, etc. I occasionally photograph a flock of herons who live nearby, but lately have noticed that I've been coming home with more and more photos of the gulls that fish, scavenge, and perch in the same area. They're graceful in flight, and often quite expressive just standing around. These are great photos!

Cheers, John

Thank you for looking and taking the time to comment. I wrote above the lens + converter setup, and it was on a monopod. What is good is that while there is no autofocus at f/9.5 (f/2.8 - 2 stops - 1.5 stops) the VR still functions normally and that helps tremendously with focusing.

I had the whole concoction stopped down one more stop to mitigate the possible softness and flare/glare issues introduced by the teleconverters, so the images were shot with 1020 mm @ f/13.5. I don't know if the stopping down actually helped any, it may be that diffraction increased just as much as lens softness decreased. But as it is I am pleased with the results of relatively static subjects.

In my opinion, 1500/long side is fine...large but not huge.My main concern is to give the image the quality it needs(pixel dimensions), while at the same time to reasonably conserve server space(file size). I try to keep the files at or below 2 megaBytes in file size. The pixel dimensions can be whatever you want, depending on how well the image survives the compression to approx 2mB. 1200 pixels on the long side seems to have been accepted as a basic norm, but 2000 or more is common, especially if there is rich detail, a wide aspect ratio, or you'd like the viewers to be able to see it 'bigger" if opened in a separate window.